Subject: Re: E-lisp primitives unextendible [was: Lisp versus C++ for AI. software]
From: Erik Naggum <>
Date: 1996/11/01
Newsgroups: comp.lang.lisp,comp.lang.c++,comp.emacs
Message-ID: <>

* Bill Dubuque <>

| The C-implemented e-lisp primitives are certainly not 100% compatible
| with those implemented in e-lisp.  For example, one cannot advise (or
| redefine) them because there is often C-level calls to such primitives
| and such C-level calls do not call indirectly through the symbol-function
| cell.  Such "hardcoded" calls make it extremely difficult to implement
| extensions to Emacs (witness the convoluted code due to loops that had to
| be jumped through to do things like ange-ftp, etc).

FWIW, there is also the byte code machine, which performs a number of
operations directly without calling any functions.

Those who do not know Lisp are doomed to reimplement it.